Lifting jack



Au@ 27, 1935. o'. F. KUHLMAN 2,012,430

LIFTING JACK Filed May 5l, 1934 mv NToR 05042 abz/wmv Patented Aug. 27, 1935 UNITED STATES PATENT orties LIFTING JACK Oscar F. Kuhlman, York, Pa., assigner to American Chain Company, Inc., Bridgeport, Conn., a corporation of New York v Application yMay 31, 1934, serial No. 728,250

8 Claims.

The present invention relates to lifting jacks and more particularly to jacks of the 'type adapted to raise both front wheels oi an automobile simultaneously.

An object of the inventionis to'provide a jack adapted particularly for use with automobiles having so-called knee-action front Wheels, that is, wheels which are individually sprungand capable of individual vertical motion with respect to the chassis.

Heretofore jacks have been designed to engage a chassis at a point midway between the front wheels, but inthe case of knee-action structures such application of the jack would result Vinitially in merely expanding the springs as`1they were relieved of the weight of the chassis and the wheels would not leave the ground until the chassis was raised beyond the limit of expansion oi the springs. This necessitates operating the jack to a much higher elevation than with cars `not having the knee-action, which entails useless'effort, and in some cases the jacks are .incapable of operating to a sufficient height to lift the kneeaction wheels oir the ground.

An object of the present invention is to provide a jack adapted to engage the knee-action mechanism instead of the chassis, so that when the jack is operated it will lift the wheels off the ground without having first to allow for elongation of the springs.

Another object of the invention is to provide `a dual rest-plate which may be substituted for the ordinary rest plate of a jack, said dual rest-,plate having a wide span so as to engage such part of the knee-action mechanism as will insure lifting of the wheels from the ground without the necessity of taking up elongation of the springs.

Another object of the invention is to provide a dual rest-plate having individual work supports or chairs pivotally mounted so that they will adapt themselves individually to the knee-action mechanism which they support.

Other objects and advantages of my invention Will appear in the following description of a preferred embodiment and thereafter the novelty and scope of the invention will be pointed out in the claims.

In the accompanying drawing;

Figure 1 is a view in perspective of a jack provided with a dual rest-plate supporting the front end of a car having knee action front wheels;

Fig. 2 is a view in longitudinal section of the dual rest-plate, the section being taken on the line 2-2 of Fig. 3; and y Fig. 3 is a top plan view of the dual rest-plate.

(ci. :zar-89) Knee-action mechanism varies with differ- `ent'makes of cars, but a typical knee-action linkage may be seen in Fig. l. The car, fragmentally shown in said gure, has a chassis lo to which front wheelsY I `I are connected by suitable links. `There are `two lower links i2and i3 for each wheel,l which "linksare hinged to the chassis. Each lower pair of links carries a seat member i4 forthe lower end of `a coil spring i5, the upper end of which bears against a suitable seat i5 car- `10 ried by the chassis. Thus, each wheel s free to swing vertically with respect to the chassis independently of the other Wheel, such vertical movement effecting expansion or contraction of the spring I5 associated with said wheel. i5

It will be obvious that when a jack is applied to the chassis inthe usual manner it will lift the weight of the chassis oi the springs it permitting the latter to expand, and the wheels will remain on the ground until the entire spring expansion has taken place or until some stop is encountered, such, for instance, as bottoming of the shock absorbers commonly provided on. the front wheels.

The jack l1, shown in Fig. 1, may be of standard make, having a plunger or lifting arm i8 adapted to support the usual rest-plate. As Shown in Fig. 1 the lifting arm is bifurcated at its upper end and a socket member i9 is embraced between the arms, being pivoted thereto by means of trunnions (not shown) so that the socket member is capable of movement about a horizontal axis. The socket member has a vertical socket or bore 20 therethrough adapted toreceive a stud projecting from the bottom of the rest plate.

Instead of the ordinary rest-plate which is adapted to engage a very limited portion of the chassis, I provide a dual rest-plate indicated generally by the reference numeral 2i. This dual 40 rest-plate, as shown clearly in 2 and 3, comprises a beam formed of a pair of arms 22. A central block 23 connects these arms in parallel and mutually spaced relation. This block has a downwardly projecting stud 24 which is turned 45 to t the socket 2 so that the rest plate may swivel with respect to the socket member. The beam provides suflicient reach to engage the spring seats I4 or such other parts of the kneeaction mechanism as would be most suitable.

Supported on the beam at each end thereof is a chair 25. Each chair is in the form of a plate preferably having an upstanding rim 2t about a part of its periphery. Extending downwardly from each plate are lugs 21 which are pivotally 55 connected to the arms 22 by means of a hinge pin 23. As shown in Fig. 2, the chairs 25 are supported slightly above the level of the arms 22 so that they are allowed limited oscillatory movement on the pins 2B. Each chair is formed with pads 2Q at the inner end of the plate, which normally rests on the arms Z2, as .shown in Fig. 2. However, the chairs may be oscillated to the position shown in Fig. l so as to adapt themselves to the parts they engage.

Preferably, the dual rest-plate is not made a permanent part of the jack but is merely connected thereto by inserting the pin or stud 24 into the socket ZD whenever it is desired to adapt the jack for lifting the knee-action wheels. At other times,

the dual rest-`plate may be removed and replaced with an ordinary single rest-plate which will adapt the jack for use on cars not equipped with linee-action mechanism.

As applied to a car of the type shown in Fig. l, the jack is maneuvered under the forward end of the chassis until the chairs 25 are substantially centered under the spring seats Elik Then when the jack is operated to raise the arm I8 said spring seats will be lifted raising the Vwheels without any useless spring extension. The rimsZE are provided as safety means to retain the spring seats in the chairs.

While I have described a preferred embodiment of my invention it will be understood that this is to be taken as illustrative and not limitative and that reserve the right to make various changes in form, construction and arrangement of parts without departing from the spirit and scope of the following'claims.

I claim:

l. A lifting jack having a lifting member and a dual rest-plate carried thereby, said rest-plate comprising a transverse beam mounted to swivel with respect to said member on a substantially vertical axis, and a pair of chairs mounted at opposite ends of the beam and adapted to oscillate in the plane of the beam on substantially horizonal axes.

2. A lifting jack comprising a lifting member, a socket block pivotally mounted in said member and adapted to turn on a horizontal axis, a transverse beam removably mounted on said block and having a swivel stud engaging the socket of said block, and a pair of. chairs pivotally mounted at opposite ends of said beam and having limited oscillatory movement in the plane of said beam.

3. A liftingY jack having 'a lifting member, and

a dual rest plate carried thereby, said rest plate comprising a transverse beam mounted to swivel with respect to said member, and a pair of chairs mounted at opposite ends of the beam and adapted to oscillate in the plane of the beam on axes lying in a plane normal to the axis on which the beam swivels.

4. A lifting jack comprising a lifting member, a socket block pivotally mounted in said member and adapted to turn on a substantially horizontal axis, a transverse beam having a swivel stud engaging the socket of said block, and a pair of Vchairs pivotally mounted at opposite ends of said beam,vthe pivotal axes of the chairs lying in a plane normal to the axis of said stud.

5. A lifting jack comprising a lifting member, a socket block pivotally mounted in said member and adapted to turn on a substantially horizontal axis, a transverse beam having a swivel stud engaging the socket of said block, and a pair oi chairs pivotally mounted at opposite ends of said beam, theY pivotal axes of the chairs lying in a plane normal to the axis of said stud, said chairs overlying the beam and being limited thereby in their oscillatory movements.

6. As an article of manufacture, a rest plate for axlifting jack, said rest plate comprising a supporting'beam, chairs pivoted on the beam adjacent opposite ends thereof and adapted to swing in the plane of the beam, and means at the center of the beam for effecting a swivel connection of the beam to the jack, the pivotal axes of the chairs lying in a plane normal to the swivel axis of the beam.

7. As an article of manufacture, a rest plate for a lifting jack, said rest plate comprising a .supporting beam, chairs pivoted on the beam adjacent opposite ends thereof, and means at the center of the beam for effecting a swivel connection of the beam to the jack, the pivotal axes of the chairs lying in a plane normal to the swivel axis of. the beam, said chairs overlying the beam and being limited thereby in their oscillatory movements.

8. As an article of manufacture, a rest plate for a lifting jack, said rest plate comprising a supporting beam having ce itral depending stud adapted for swivel connection to the jack, a pair of chairs pivoted respectively adjacent opposite ends of the beam, the pivotal axes of the chairs ly ing in a plane normal to the axis cf said stud, and cooperating means on the chairs and beam for limiting oscillation of said chairs.

OSCAR F. KUHLMAN. 

